Continuous-current dynamo-electric machine



Det. 18, 1928. 12,696,102,

` l A. sci-mm .Er-AL n conrmuous CURRENT www nLEcrnIc lucani! FiledApril 5, 1927 Patented Dec. l 18, A19.28.

UNITED'STATES M'rlalN-'r OFFICE.

mon Aim anousrom., or s'rurraaar, GERMANY, assmnons 'ro nonna'r nommen rf 0F STUTTGART, GERINY.

oen'rnluou mmanomc'rarc incanta.

application mea Aprn l, im, und lo. 181,054, ma 1n Germany apra 15,192e. l I

In order to make small electrical motors reversible, so as to rotateeither in lefthand or right-handsense, ordinarily junction-bars are usedwhich may be laid luto one of the a positions for roperly connecting up.the motor electrica yto cause itto rotate 1n the desired direction.These junction-bars may be dispnsed with, if at the terminals of thefield windin and at the brushes exch lo able cable en are used which aresuslpen ed for some length therefrom. Such cab e-ends, however, areinconvenient within the limited interior space of small electricalmachines. Accordin to our invention these cable ends are.entire yavoided by having the connections for both vends of the field windingfastened on the support for the bearing'at the commutator side of themotor and diametrically opposed with respect tothe axis of the armatureLof the motor. In order to change the direction of rotation of the motorit will be suflicient to vdisconnect the terminals of the field'windingand to rotate said support for the bearing at the commutatbr sideagainst the motor casing throu h an angle of 180, whereupon the ends osaid fie d winding may be fixed to the connections serving for lthereversal ofv the motor. In the accompanying 'drawing an example of anelectric motor is shown which is constructed according kto ourinvention; the motoris shown a's lbein constructed as a fourpole seriesmotor which serves for the startin o combustion engines. 5 1 n 1g. 1 isa sect-ion taken through the com-v mutator side of the new motor andFig. 2 showsthe electrical connections of the same. Y

In Fig. 1, the numeral 1 designates the motor casing, 2 the motoramature, 3 the field windin 4 and 5 the terminals thereof, 6 one of. therushes and 7 the support for the armature bearing at the commutator sideof the motor, said support being fixed b means of screws 8 on the motorcasing 1. wo connecting pieces 9 and 10 are rovided on the support insuch a position t at they are displaced relatively to each other by anangle of 180. The two terminals 4 and 5 of the field winding are passedthrough the motor casing by means of two diametrically o posed bores, asindicated in the drawing. T e terminal 4 ma be connected to theconnecting piece 9 an the terminal 5 to the connecting iece 10 whichleads at the same time to the E rush 6.

The other brush is positioned' rec ly to said brush 6. A connectionl 11lea s from the connecting piece 9 to the positive pole of a battery.

`When it is desired to reverse the direction of rotation of the armature2, the terminals 4 and 5 of the field winding of the motor are.disconnected from the connecting pieces 9 and 10 and thereupon thescrews 8 are re leased and the bearing support 7 together with bothbrushes rotated' through an an le of 180 and'then fixed in such positiony the 'screws 8 to the motor casing 1. The convne'ctions for the fieldwinding are thereby reversed; more particularly speaking, the connectingpiece 9 will be connected with the ter minal 5 of the field winding andtheconnecting piece 10 with the terminal 4 thereof. The connectionbetween the .connecting piece 9 and the battery will not be changed bytherotaton of the bearing support 7; in like manner there will be nochange in the connection between the connecting piece 10 and the brush6. The two brushes 1n their new position with respectto the armaturepoles `will be the SallieA as before, the direction of the current,however, which flows through the eld winding will have been reversed sothat the armature will rotate in the opposite direction.

Instead of rotating the bearing support 7, 'or, what will have the sameeffect, the motor casing through an angle of 180, the field winding maybe displaced with respect to its original position by 180, for changingthe direction of rotation of the motor.

This may also be seen from the` electrical connections of the motor asshown in 2, in which the field system is designated by the referencenumeral 12 and the bearing support at the commutator side of the motorwit the reference numeral 13. The connecting piecel 14 is connected withthe one terminal of the Vfield winding and connecting piece 15 with theother terminal thereof. In addition to this there is a connectionleading from the connecting piece 14 to the battery 16 Vand from theconnecting piece 15 to thepositive brush 17. The negative brush 18 isgrounded or connected to the body of the motor. In order to change thedirection of rotation either the bearing support- 13 together with bothbrushes 17 and 18 or also the field system may be rotilted by 180 inorderto accomplish the re-v versal ofthe motor.

In case the field system of the motor comprises two separate windings,for instance a main Winding and an auxiliary winding, the terminals ofsaid windings may be connected in proper sense With correspondingconnecting pieces provided at the bearing support. The change of thedirection of rotation of the motor will then be accomplished in the samemanner as with the single field Winding.

We claim:

1. A continuous-current dynamo-electric machine adapted for rotation inforward or reverse direction, said machine comprising a bearing supportfor the armature, a field Winding, and connecting pieces for the ends ofsaid field Winding, said connectinff pieces being provided on saidarmature bearing snpport and positioned diametrically relatively to eachother and to the axis of rotation of said machine, and means'forseedling said connecting pieces in positions with respect to thefield-winding which are displaced by 180O relatively to each other,whereby the field- Winding connections may be reversed with respect tothe armature.

2. A dynamo-electric machine as specified by claim l, having theterminals of the field Winding passing out of the machine casing atpoints which are positioned diametrieally opposite to each other and inproximity to the connecting pieces.

3. A dynamo-electric machine as specified by claim l, having a bearingsupport. which is adapted to be fixed at the machine. easingr in twopositiones which are displaced by 1800 against each other.

4. In a dynamo-electric machine as specified in claim l, the arrangementof a four-pole field in combination with commntator brushes arranged atright angles to one another.

In testimony whereof we have hereunto aiXed our signatures.

ADOLF STOLL. ANTON SCHMID.

